Automatic compensating centrifugal governor



Feb. 13, 1945. w. E. BENJAMIN AUTOMATIC COMPENSATING CENTRIFUGALGOVERNOR Filed Jan. 30, 1943 2 Sheets-Sheet l Feb. 13, 1945.

w. E. BENJAMIN 2,369,426

AUTOMATIC GOMPENSATING CENTRIFUGAL GOVERNOR 2 Sheets-Sheet 2 Filed Jan.30, 1943 INVENTOR.

Patented Feb. 13, 1945 UNI-TED STATES PATENT OFFIC AUTOMATICCOMPENSATING CENTRIFUGAL V GOVEBNDR Walter E. Benlamin, Anderson, Ind.,assigner to Pierce Governor Company, Anderson, Ind.

Application January 30, 1943, Serial No. 474,095

14 Claims. (Cl. 12S-108) butterfly type and is mounted in a,throttlebodyinserted between the carburetor and intake manifold. The balancedvalve eliminates to a great extent the velocity effect of the fuel`'supply thereon over the unbalanced valve, hence is preferred.

In governing lof the aforesaid character the control structure-.isdirectly responsive to engine speed, and in the typejllustrated. staticand velocity pressures on governing valves vary, so that the torqueexerted thereon by fuel mixture flow through the engine intake variesfor different speeds and loads, etc. f"

The chief object of this invention is to offset this uneven torquepressure on the governing throttle valve, so that the latter .m trulydirectly and proportionally responsive to the centrifugal `controlimposed on said valve.

The result is that extremely close governor regulation between no loadand full load is possible, because the torque reactions on said valvebetween these loads is properly compensated for. l

The chief feature of this invention resides on the inclusion of governorvalve torque pressure compensator in the form of a cam and followerstructure that is arranged to impose a force on said valve at anyposition thereof substantially equal and opposite to the fuel mixtureflow torque imposed thereon, with the result that there is in effect anegligible pressure result, or a pressure that is substantially constantfor the full range of throttle valve travel.

'I'he present invention is, as evidenced by the charts, a substantiallyperfect exempliflcation of the basic invention disclosed in thecopending application Serial No. 452,883 filed July 30th, 1942 althoughsame is confined to a velocity governor only and incorporates therein `acompensating factor.

The present invention in like manner produces results that arephenomenal in that almost vertical line effect results at any governedspeed for all loads. No governing structure known to date is comparablethereto. Applied to military equipment, as it now is, this inventionholds the engine to the governed speed, so that approximately 25 B. H.P. additional is now available for hill climbing purposes and about fourmiles per hour more speed is available over the entire range of from noload to full load, for governed speed at full load.

Other objects and features of the invention will be set forth more fullyhereinafter.

The full nature of the invention will be understood from theaccompanying drawings and the following specications and claims:

In the drawings Fig. 1 is a diagrammatic central sectional view of aconventional centrifugally operable device, a side elevation of agovernor throttle body, the power connection therebetween and e, sideelevation of the valve torque compensating structure, parts being shownin the wide open throttle position, dotted lines indicating the governorvalve closed throttle position.'

Fig. 2 is an end elevational view of the throttle body with governorconnection and compensating structure attached.

Fig. 3 is a diagram of two curves from wide lopen throttle to closedthrottle over a full range horsepower load against speed, and the thirdshowing beam load of the brake against speed, the former all being thevariable and the latter being substantially 2400 R. P..M. These curvesare substantially constant vertical lines indicating constant regulationat any load and for different manifold pressure evidencing substantiallyexact and complete compensation from no load to full load at a givenspeed.

Fig. 5 is a diagrammatic side elevation of an engine including aircleaner, carburetor, manual 'r throttle, manifolds, throttle body,governor (engine driven) and connection therefrom to throttle valveshaft in the throttle body X indicating the valve and Y the manualcontrol.

The corresponding curves for the device set forth in the copendingapplication show a slight inclination crossing the selected speed nearthe higher vacuums or positive pressures and high load markedly broke tothe left'in this range.

Valve torque compensation being substantially perfect in the presentinvention, there is none to transmit to the governor, so that surgingback and forth to correct over a limited range (hunting) substantiallyis eliminated to a degree heretofore unknown in a centrifugal governormechanically connected to a throttle valve.

In Fig. l of the drawings, I indicates a housing of a centrifugallyoperable structure secured to a portion of the engine by bolts II andhaving a lateral opening by which a gear I2, keyed at I3 to thecentrifugal shaft I4, can engage and mesh-with an engine, or enginedriven gear, so that shaft I4 is rotatable at, or proportional to enginespeed.

Shaft I4 is rotatably supported in anti-friction bearings I5 and I6, thelatter being mounted in the housing extension Illa. Longitudinallyslidable on, but rotatable with shaft I4, is sleeve I1. Rigid with shaftI4 is base I8, to which is pivoted at 9 the centrifugal force responsiveweights 20, having tail or finger portions 2I positioned adjacent oneend of sleeve I1.

At a predetermined engine speed, determinable by the load springadjustment and spring selected, these weights, due to centrifugal force,tend to move outwardly and upon doing so, their tail portions slidesleeve I1 upon shaft I4. Herein sleeve I1 is illustrated as mounting anantifriction bearing member 2-2 at the end opposite the tail engageableportion.

A yoke lever pivoted at 23 has spaced portions 24 engageable by bearing22. Thus the lever 25 is tiltable byv weight movement responsive tocentrifugal force. A load spring 26 bears at 21 upon lever 25, beingretained thereon by stem guide 26. Housing .I0 is threadedly aperturedat 29 and an externally threaded socket type cap, having socket. 30 andknurled head 32, seats the other end of said spring. and may be manuallyrotated, respectively. for adjusting the initial force of such loadspring. Look nut 3l holds the adjustment.

This spring normally opposes centrifugal movement of the weights at alltimes. When the centrifugal force is sufllciently great, the weightsmove, as described, and hence tilt lever 25. This is the control leverand is usually connected to the governing member, such as a butterflyvalve in a passage through a throttle body in the engine intake system.

All of the aforesaid describes a conventional centrifugal governor, andin the present invention the same is not disturbed, but the effect ofother forces, as initially described herein, are of such character thatthis theoretical operation is modified to that extent. The presentinvention automatically compensates for such forces, so

. that the actual governing operation is substantially the theoreticaloperation.

Herein, see Fig. 1, lever |25 outside of the governor housing and rigidwith shaft 23, supports a pin type end 33 of a rod 34, which may be ofadjustable length type. At its opposite end, this rod is pivotallyconnected at 35 to a lever arm 36, rigid with an exposed end of throttleshaft 31, pivoted in throttle body 38 interposed in the engine intakesystem downstream of the carburetor and usually between the carburetorand engine manifold connecting flanges, see Fig. l.

Herein shaft 31 projects through the body and on 'its other exposed endmounts another arm 4I pinned thereto as at 42. This shaft may be mountedin anti-friction bearings (not shown). The free end of arm 4I mounts onpivot 44, the

roller or follower 46. An anti-friction race 43 may be interposedbetween pivot 44 and roller 45 wherever desired or required. l

The aforesaid several anti-friction bearings broadly are conventional tostandard governor practice, wherefor same are not illustrated in detail.

Pivotally supported at 46 on the throttle body,

and adjacent arm 4I, is member 41. 'I'he roller and member 41 lie in acommon plane. Member 41 is of bell crank type with arm 48 having flatface 49 perpendicular to line A-B and lying in the plane including theaxis of shaft or pivot 46. Roller 45 contacts face 49 at all times. Theother arm 50 of -bell crank 41 has eye 62 in its outer end and thecenter thereof lies in'plane A-B. Accordingly, plane of face 49 is atright angles to center of the eye 52.

A light spring 5| has one end secured to eye 52 and its. opposite end issecured to eye 53 in the anchor member 64 threaded into boss '55 onplate 56 rigid with the throttle body. The spring ends are aligned atwide open throttle, for the longitudinal axis of anchor member 54 liesin plane A-B. The tension of this spring, which is light, but sufficientfor compensating purposes, can be adjusted by moving member 54 towardand away from the axis of pivot 46.

Obviously the spring 5I always constrains the face 49 into rollercontact, so that the force of this spring tends to hold the valve openand in an amount equal to the torque on-the valve imposed by fuel ow inthe intake when the governor valve is moved toward closed' position.This torque is in the valve closing direction, The spring force isopposed thereto.

Now, as the valve is governor closed the arm 48 must move clockwise. InSo doing arm. 50 moves therewith. Now, since spring 5I is under initialtension, it, when the arm is so moved elongates or stretches, hence itsforce increases as the arm is moved.

Y Here follows the gist of this invention and -the key to its success.Observe, see Fig. l, that at open valve position the arm 4I liesparallel to arm 48. f When spring 5I is adjusted, this is the idle ornon-governing position. With a balanced valve the fuel flow torquethereon is zero, see

curve Fig. 3.

Now, with a 60 throttle valve movement to closed throttle, the arm 4I isthen transverse to arm 48. Also, the torque curve again is zero, becausenow no fuel flows in the intake. However, at this position spring 5I ismore elongated than ever.

With the valve half open, the torque is greatest. In this position arms4I and 48 are midway vbetween the aforesaid limiting positions andspring 5I is elongated, but partially from idle zero position to itsfinally extended position.

The actual effective spring balancing force, accordingly, from 30 to 60of throttle valve is proportionately decreased despite its (the spring)extension or increase. 'Ihis is because so far as arm 4I is concerned,the pressure of arm 48 thereon, effective to throw the valve open,if'the governor force be removed, (or flip open) is only the decreasingregular function thereof,

- from 30 to 60, respectively.

This explains why there is not an absolutely vertical line in Fig. 4,and this angular function cancellation is exactly equal in amount at allvalve positions to produce an actual sine curve balancing force, comparethe two curves in Fig. 3.

ascuas However, the curves are so close as to be substantially identicalwith the results described.

The mechanical advantages of the present invention over that disclosedin the pending application are that first in common therewith alongitudinally extensible spring is utilized, but herein the adjustmentpossible can be of micrometer variation, which is impossible in theassemblage of said application. This means that the slight variationswhich always are present in a lotof commercial springs of a specifieddiameter, length and force, can` be readily adjusted for. in effecteliminated, so that accurate spring selection is not required. A moreimportant advantage, however, exists in that a iiat face is always aflat face and, hence, no variation occurs in manufacture. Such is notthe case with the sinusoidal face of the application cam. The leastvariation in the face at any point will introduce an error in thecorrection desired. Also, there is a mechanical function errorinherently present in said pending application structure for which nocompensating internal correction is provided and this accounts for thedeparture of its curves from the curves herein, as previously mentioned.

All the aforesaid, however, is solely intended to show that presentinvention is substantially perfect, whereas the invention disclosed inthe pending application. while phenomenally better than any heretoforeknown, actually did not reach perfection, although it was very closethereto.

While the invention has been illustrated and described in great detailin ,the drawings and foregoing description, the same is to be consideredas illustrative and not restrictive in char-` The modification describedherein, as well as others which will readily suggest themselves topersons skilled in this art, all are considered to be within the broadscope of the invention, reference being had to the appended claims.

The invention claimed is:

l. In an engine governing mechanism including a substantially balancedbutterfly valve for engine intake throttle control and a centrifugallyoperable structure responsive to engine speed and directly connected tosaid valve for operation thereof, the combination of an arm rigid withsaid valve, a bell crank lever adjacent thereto, having an arm with anelongated ilat face for operatively engaging the end of the valve, atwide open throttle position the longitudinal axis of the valve arm lyingparallel to the plane of the face and at closed throttle beingsubstantially transverse thereto, said bell crank having another arm,the free end thereof forming a spring anchorage, the longitudinal lineincluding such anchorage and the lever pivot axis being substantiallyperpendicular to the plane of the face, another spring anchorage inalignment with the longitudinal line only whenl the aforesaidparallelism exists, and a coiled light tension spring secured atopposite ends to said anchorages for substantially perfect compensationfor the intake fuel flow torque on said valve for substantially allgoverned positions of said valve and constraining the bell crank tovalve arm contact.

2. A governing mechanism as defined by claim 1 wherein the plane of theilat face passes through the pivot axis of the bell crank lever.

3. A governing mechanism as defined by claim 1 wherein the spring endsare of loop character 1 wherein the spring ends are of loop characterand lie in a plane common to the longitudinal line and substantiallytransverse to the face plane. the latter plane passing through the pivotaxis of the bell crank lever.

5. A governing mechanism as defined by claim 1 wherein the secondmentioned spring anchorage is an eyeletted elongated threaded member forwide open throttle initial spring force adjustment and commercial springvariation compensation.

6. A governing mechanism as defined by claim 1 wherein thevalve armterminates in a flat face roller follower, the axis of whichroller liesperpendicular to and intersects the longitudinal axis of said valve arm.

7. A governing mechanism as deilned by claim 1 wherein the valve armterminates in a ilat face roller follower, the axis of which roller liesperpendicular to and intersects the longitudinal axis of said arm, andthere is included an anti-friction support between the roller followerand the valve arm.

8. A governing mechanism as dened by claim 1 wherein the valve armterminates in a ilat face roller follower, the axis of which roller liesperpendicular to and intersects the longitudinal axis of said valve arm,and the second mentioned spring anchorage is an eyeletted elongatedthreaded member for wide open throttle initial spring force adjustmentand commercial spring variation compensation.

9. A governing mechanism as deilnedby claim 1 wherein the valve armterminates in a at face roller follower, the axis of which roller liesperpendicular to and intersects the longitudinal axis of said valve arm.and there is included an antifriction support between the rollerfollower and said valve arm, and the second mentioned spring anchorageis an eyeletted elongated threaded member for wide open throttle initialspring force adjustment and commercial spring variation compensation,

10. A governing mechanism as defined by claim 1 wherein the valve armterminates in a iiat face roller follower, the axis of which roller liesperpendicular to and intersects the longitudinal axis of said valve arm,and the plane of the dat face passes through the pivot axis of the bellcrank lever. 1

11. A governing mechanism as defined by claim 1 wherein the valve armterminates in a at face roller follower, the axis of which roller liesperpendicular to and intersects the longitudinal axis of said valve arm,and there is included an antifriction support between the rollerfollower and the valve arm, and the .plane of the flat face passesthrough the pivot axis oi' the bell crank ever.

12. A governing mechanism as defined by claim l wherein the spring endsare of loop character and lle in a common plane and common to thelongitudinal line and substantially transverse to Y longitudinal lineand substantially transverse to the face plane, the latter passingthrough the pivot axis of the bell crank lever, the second mentionedspring anchorage is an eyeletted elongated threaded member for wide openthrottle initial spring force adjustment and commercial spring variationcompensation.

14. In an engine governing mechanism including a substantially balancedbutterfly valve for engine intake throttle control and a centrifugallyoperable structure responsive to engine speed and directly connected tosaid valve for operation thereof, the combination of an arm rigid withsaid valve and a single elongated tension spring anchored at one end andoperatively connected at its other end to said arxnv remote from thevalve axis thereof, said arm at open valve position having a generaldirection angular to the plane of the valve, the general direction ofthe spring at open valve position being angular to said arm and theplane of the valve, the spring-arm relationship at open valve positionbeing such that substantially no springforce is eiective upon the valve,and at closed valve position substantially no springv force is effectiveupon the valve, `the force, direction and eil'ect of said spring varyingtherebetween for loading the valve tocompensate for velocity eil'ectthereon .betwen said extreme positions thereof, the spring inintermediate valve positions, pulling towards open valve position.

WALTER E. BENJAMIN.

